Optical signals that travel from a central office to customer premises over optical fibers (beyond 20˜50 kilometers) will be attenuated due to fiber loss and distorted due to optical dispersion. In some instances, fiber loss occurs when optical signals transition from one optical fiber to another optical fiber via a fiber optic connector that aligns and secures the optical fiber ends. To ensure the integrity of optical signals, an engineer or a technician may test fiber optic connectors for cleanliness of and possible damages to optical fiber ends inside the fiber optic connector.